Reference may be made to the following U.S. Pat. Nos.: 4,101,284; 2,561,339; 2,781,947; 2,838,204; 3,342,318; 3,294,284; 3,446,397; 2,683,551; and German Pat. No. 866,981.
The use of solid supports referred to hereinafter as beads, dispensed into reaction containers or wells in conducting immunologic assays is described for example in the aforementioned U.S. Pat. No. 4,101,284. Presently available multiple bead dispensers generally provide a slidable plate having a plurality of apertures each to be filled with a bead from a bead reservoir. The plate may then be moved to align the plate apertures with a plurality of corresponding outlet apertures to enable dispensing of the beads. However, the beads have a tendency to hang together and bridge across openings, rather than falling directly into each of the plate apertures, thus dispensing less than the anticipated and desired number of beads.
Bead dispensers in the form of an elongated cylinder with a tip deformable to dispense a bead at a time are also available. While useful under certain circumstances, occasionally dispensing becomes erratic due to a deformed cylinder or sticking of beads under extreme humidity conditions.
It is therefore desirable to provide a reliable bead dispenser of relatively inexpensive construction. Further, it is desired to provide such a bead dispenser which can rapidly and reliably dispense beads one at a time from a plurality of beads.